arch/arm64/include/asm/mmu.h


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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_MMU_H
#define __ASM_MMU_H

/*
 * VMSAv8-64 stage 1 translation at EL2. descriptor layouts and
 * attribute fields per the ARM ARM (DDI 0487), block and table
 * descriptors D5-2444, page descriptors D5-2447, stage 1 attribute
 * fields D5-2451, MAIR region attributes D5-2476.
 */

#include <stdint.h>

/* descriptor bits[1:0]: 0b01 block (page at level 3), 0b11 table */
#define TB_DESC_FAULT		0ULL
#define TB_DESC_BLOCK		1ULL
#define TB_DESC_TABLE		3ULL

/* lower block/page attribute bits, D5-2451 */
#define TB_DESC_AF		(1ULL << 10)	/* access flag, set by hand */
#define TB_DESC_SH_IS		(3ULL << 8)	/* inner shareable */
#define TB_DESC_XN		(1ULL << 54)	/* XN at EL2, no execute */

/* MAIR_ELx attribute indices used by the maps below */
#define TB_ATTR_NORMAL		0		/* writeback, read allocate */
#define TB_ATTR_DEVICE		1		/* device nGnRE */

/*
 * TCR setup, 4KB granule. T0SZ 16 gives a 48-bit VA and the walk
 * starts at level 0 (Address size configuration, D5-2399), which is
 * what the three level table structure below assumes. a 39-bit VA
 * (T0SZ 25) would start the walk at level 1 and misread the whole
 * table.
 */
#define TB_TCR_T0SZ_48		16
#define TB_TCR_SH0_IS		(3ULL << 12)
#define TB_TCR_TG0_4K		(0ULL << 14)
#define TB_TCR_IRGN0_WB		(1ULL << 8)
#define TB_TCR_ORGN0_WB		(1ULL << 10)
#define TB_TCR_IPS(x)		((uint64_t)(x) << 16)	/* PA size from PARange */

/* the map itself, PA == VA everywhere, identity */
#define TB_MAP_MMIO_BASE	0x00000000ULL
#define TB_MAP_MMIO_SIZE	(1ULL << 30)	/* low 1GB, devices live here */
#define TB_MAP_RAM_BASE		0x40000000ULL
#define TB_MAP_RAM_SIZE		(128ULL << 20)	/* qemu virt default, 128MB */

int tb_mmu_enable(void);
void tb_mmu_disable(void);

#endif /* __ASM_MMU_H */